Robin Hanson debunks the notion that speculators and manipulators are responsible for rising gas prices.
Eugene Volokh debunks the oft-made claim that free speech laws in the US do not, somehow, apply to ‘hate speech’.
Jim Lindgren debunks internet rumours about Michelle Obama.
I’m not sure that the post debunks the rumors about Michelle Obama, but I never took the rumors seriously anyway.
Here’s some more investigation on the tape rumours. I’d say that the debunking has been done to the extent it is possible (given that the accusations were incredibly vague to begin with).